Methods of automated milking of animals are known. When an animal visits the milking parlor, it is decided on the basis of a milking criterion whether or not the animal will be milked. European Patent EP-A-0 091 892 describes a system in which a cow is milked in the milking parlor, after at least a predetermined period of time has elapsed since her last milking. This has inter alia the disadvantage that mutual differences between animals to be milked are not taken into account. Moreover, it is necessary to measure each time for each animal the beginning and the end of the milking and to record these data, which requires measuring equipment that is sensitive to interference and occupies a relatively large amount of memory capacity.
From International Patent WO-A-95/35028 it is known to use as a milking criterion the number of milkings of other animals which have occurred since the previous milking of the relevant animal; in this situation the animal is milked when this number at least equals a specific minimum number, which may differ for each animal. This milking criterion can be practiced with the aid of simple and cheap means.